Finite Element Research Of Concrete-filled Circular Steel Tubular Column Mechanical Properties Under Welding High Temperature

Concrete-filled steel tubular columns are formed by steel tube and concrete.Through stressed process of interaction between the steel tube and the concrete,namely concrete with the restriction of steel tube caused complex stress state,the concrete strength,plasticity and toughness properties are much improved.At the same time,the concrete has the characteristics of mutual complementary and contribution,collaborative work between steel tube and concrete,the structure also has good high-temperature resistance.In reversed engineering,when the external concrete-filled circular steel tubular column lapped beam,welding steel tube in the outer ring plate to support internal steel frame beam.The heat generated during welding is transferred to the concrete through a circular steel tube.With the increase of temperature in concrete,aggregate and cement due to expansion,internal stress in the constraints of circular steel tube,lead to severe stress concentration,the formation of micro cracks,thereby reducing the strength of core concrete.Making influence of mechanical properties and ultimate bearing capacity of concrete-filled circular steel tubular columns.Therefore,the study on the change of the mechanical properties of the concrete-filled circular steel tubular columns under the welding temperature field and the load has certain engineering significance.In this paper,the change about stress-strain relationship and the ultimate bearing capacity of concrete-filled circular steel tubular column under the high temperature and under axial load are main studied.Through the finite element software ABAQUS and ANSYS simulate research of concrete-filled circular steel tubular column outer ring plate position distribution of temperature field under welding high temperature,and outer ring plate of concrete-filled circular steel tubular column based on the temperature field,Study on mechanical properties of core concrete under axial load.The results indicate that,when the outer ring plate welding position temperature rises to approximately 400?,Under the influence of the welding temperature field,the yield stress of the core concrete is reduced obviously,when the axial load is applied the bearing capacity about the concrete sectionof the circular steel tube column is significantly decreased.The purpose of this paper is to provide some reference for practical engineering design and construction.